An OLED is disclosed whose emissive layer has a first host and an emitter, where the emitter is a phosphorescent metal complex or a delayed fluorescent emitter, where E.sub.H1T, the T.sub.1 triplet energy of the first host, is higher than E.sub.ET, the T.sub.1 triplet energy of the emitter, where E.sub.ET is at least 2.50 eV, where the LUMO energy of the first host is higher than the HOMO energy of the emitter, where the absolute value of the difference between the HOMO energy of the emitter and the LUMO energy of the first host is ?E1, where a??E1?E.sub.ET?b; and where a?0.05 eV, and b?0.60 eV.

A compound of Formula I,

##STR00001##

is provided. In Formula I, M is Pt or Pd; moieties B, C, and D are independently a monocyclic ring or a polycyclic fused ring system; moiety E is a monocyclic ring or a bicyclic fused ring system; n is 0, 1, or 2; K and K.sup.1 to K.sup.3 are independently a direct bond or a linker; Z is C or a heteroatom; each of Z.sup.1 to Z.sup.3 is independently C or N; X is CR, CRR, NR, or PRR; each of X.sup.C, X.sup.D, X.sup.1 to X.sup.3 and X.sup.8 to X.sup.12 is independently C or N; L.sup.1 is a direct bond or a linker; L.sup.2 is absent a bond, a direct bond, or a linker; each of Q.sup.1 and Q.sup.2 is a direct bond or a linker; each R substituent is independently hydrogen or a General Substituent. Formulations, OLEDs, and consumer products containing the same are also provided.

An organic light-emitting device including a first electrode, a second electrode facing the first electrode, and an organic layer disposed between the first electrode and the second electrode, wherein the organic layer includes an emission layer, wherein the emission layer includes a thermally activated delayed fluorescence (TADF) emitter and a host and the TADF emitter is different from the host, and wherein the TDAF emitter is capable of satisfying certain conditions disclosed in the specification.

The present disclosure provides a nitrogen-containing heterocyclic compound having general formula (I) and an organic photoelectric apparatus thereof.

##STR00001## where A.sub.1, A.sub.2, A.sub.3, A.sub.4, A.sub.5, A.sub.6, A.sub.7, and A.sub.8 are independently selected from a hydrogen atom, at least one compound having the general formula (II) and at least one compound having the general formula (III),

##STR00002## where Y.sub.1, Y.sub.2, and Y.sub.3 are independently selected from C and N; R.sub.3 and R.sub.4 are independently selected from C.sub.6-30 aromatic group and C.sub.2-30 heterocyclic aromatic group,

##STR00003## wherein X is selected from any one of oxyl group (O), sulfhydryl group (S), substituted or non-substituted imino group, substituted or non-substituted methylene group, and substituted or non-substituted silicylene group; R.sub.5, R.sub.6, R.sub.7, R.sub.8, R.sub.9, R.sub.10, R.sub.11, and R.sub.12 are independently selected from hydrogen, deuterium, C.sub.1-30 alkyl group, C.sub.6-30 aromatic group, or C.sub.2-30 heterocyclic aromatic group.

Chemiluminesescence is emitted from a reaction between phenylglyoxal derivatives and guanine. This chemiluminescence can be used in CRET for the detection of one or more analytes of interest. Chemical pathways depicting the chemiluminescent reaction and intermediates produced therein are shown, as are novel nanoparticles for use in the present methods and compositions.

An organic light-emitting device having improved efficiency and lifespan includes: a first electrode, a second electrode, and an organic layer between the first electrode and the second electrode, wherein the organic layer includes an emission layer, the emission layer includes a first compound, a second compound, a third compound, and a fourth compound, the first compound, the second compound, the third compound, and the fourth compound are different from each other, the third compound includes a metal element having an atomic number of 40 or more, the fourth compound includes boron (B), the third compound and the fourth compound each satisfy Conditions 1-1 and 1-2 below, and the fourth compound satisfies Condition 2 or 3:
T.sub.1(C3).sub.onset?S.sub.1(C4).sub.onsetCondition 1-1
T.sub.1(C3).sub.max?S.sub.1(C4).sub.maxCondition 1-2
K.sub.RISC(C4)?10.sup.3 S.sup.?1Condition 2
f(C4)?0.1Condition 3.

A phosphorescent emitter or delayed fluorescent and phosphorescent emitters represented by Formula 1 or Formula II, where M is platinum or palladium. ##STR00001##

A display device comprises a light-transmittance-variable panel including a first substrate and a second substrate facing each other; a first transparent electrode on the first substrate; a second transparent electrode on the second substrate; and an electrochromic layer between the first transparent electrode and the second transparent electrode and containing a viologen compound; and a display panel on one side of the light-transmittance-variable panel and including a plurality of display units and a plurality of transparent units.

The present disclosure is directed to organic electroluminescent devices comprising thermally activated emission material(s) in an emission layer. The present disclosure is also directed to compounds capable of providing thermally activated delayed fluorescence, and to emission layers comprising at least one of the compounds. The compounds may be used in organic layers such as emission layers of an organic electroluminescence device such as fluorescent OLEDs.

Described herein are molecules for use in organic light emitting diodes. Example molecules comprise at least one moiety A and at least one moiety D. Values and preferred values of the moieties A and D are described herein. The molecules comprise at least one atom selected from Si, Se, Ge, Sn, P, or As.